Liquid-fuel system



M y 7, 1957 R. c. ALDEN LIQUID-FUEL SYSTEM Filed Jan. 4, 1954 a W Rm f Mw a 5 m ,7

ATTORNEYS ilnited States Patent LIQUID-FUEL SYSTEM Richard C. Alden,Bartlesville, Okla., assignor to Phiilips Petroleum Company, acorporation of Delaware Application January 4, 1954, Serial No. 402,121

6 Claims. (Cl. 103-450) This invention relates to an improved fuelsystem for use with an internal combustion engine using a liquid fuel.in one of its more specific aspects, it relates to a device forpreventing the vaporization of liquid fuel between the fuel supplysource and the carburetor of an internal combustion engine.

It is common practice to use an engine-driven pump for the purpose offorcing fuel to the carburetor of an automobile engine. The pump usuallyhas a diaphragm which is flexed in one direction by a moving part of theengine to draw fuel from the supply tank to fill the suction pipe andpump chamber, and in the opposite direction by a spring which exerts aresilient pressure on the fuel, tending to force it into the carburetoras it is consumed. When the fuel spaces are full of fuel and while thetemperature of the fuel remains below its vaporization point, the pumpoperates satisfactorily. However, during hot weather and especially inhigh altitudes and while the car is climbing heavy grades, vapor issometimes generated in excess of the displacement capacity of the pump.This results in the fuel space becoming partially filled with vaporwhich displaces the liquid fuel and if not arrested, finally forms thecommonlyknown vapor lock. This difiiculty becomes serious under certainconditions and causes the engine to lose power and sometimes stallbecause of insufficient fuel. Usually, it is necessary to either waituntil the engine has cooled or to pour cold water on the components ofthe fuel system in order to condense the accumulated gasoline vapor.

The present invention provides a method of minimizing vapor lock in thefuel system of a reciprocating internal combustion engine. With thepresent invention, vapor lock is almost entirely eliminated bypreventing any vapor from forming in the fuel pump through cooling ofthe critical parts of the fuel system. In this invention, the surfacesof the fuel pump adjacent to and in contact with the fuel areconstructed with an outer jacket of porous metal having a series ofaggregation of capillary tubes or holes through which water or anotherliquid contained within the jacket can diffuse onto the surface andprovide a cooling efiect by evaporation into the atmosphere. The watercan be supplied to the jacket of the fuel pump either continuously froma reservoir or intermittently whenever vaporization of the fuel in thefuel pump has occurred or is about to occur. The control of the flow ofwater in intermittent operation can be either by manually regulating avalve in the water line between the reservoir and the water jacket ofthe fuel pump or by automatically regulating a control valve in thewater line in accordance with a temperature-responsive element such as athermostat located in the inlet of the fuel pump. The water or otherliquid supplied to the fuel pump can have an anti-freeze solutionadmixed therein to prevent freezing of the system with the occurrence oflow temperatures. It is preferable to construct the water jacket of aporous metal because most metals have a high heat conductivity; however,

other, materials such as plastics, textiles, ceramics, etc. having asuitable porous structure can also be used.

The method of making porous metal articles is known as powder metallurgyand comprises placing metal powders in a mold, subjecting the powders tohigh pressure and heating the powder to a temperature below the meltingpoint of the metal. The principle of powder met'al lurgy is based on thefact that, when a solid mass of a metal is crushed to a powder, thesurface area of the particle is increased greatly in proportion to itsmass. When the metal powder is heated, the surface of each particle willreach a semi-molten state at a temperature lower than the melting pointof the metal and the particles Will become fused together to form asolid body.

Thus, the porous metal articles can be molded in the required shape orthey can be machined from blocks of the porous metal.

Each of the following objects will be attained by at least one of theaspects of the invention.

It is an object of this invention to provide a liqui fuel system for aninternal combustion engine which is substantially free from vapor lock.

It is another object to provide a porous metal waterjacket for thoseportions of the liquid-fuel system wherein vaporization of the liquidfuel tends to occur.

It is still another object to utilize a. porous metal for constricting awater jacket about a fuel pump wherein liquid fuel is used.

It is still another object to provide a means for cool ing the liquidfuel supplied from the fuel supply tank to the carburetor of an internalcombustion engine.

Other objects and advantages will be apparent to one skilled in the artupon studying the description of the invention and the attached drawingwhich is a part ofv this disclosure.

Figure 1 is a sectional elevation of a preferred form of the inventionapplied to the fuel pump of an internal combustion engine.

Figure 2 is a modification of a preferred form of the invention.

In Figure l of the attached drawing a preferred embodiment of myinvention is shown employing a manual means of controlling theapplication of water to the Water jacket attached to a diaphragm-typefuel pump 10. Fuel enters pump chamber 11 of fuel pump 10 by fuel line12 after passing through a fuel strainer and sediment bowl (not shown).Pump chamber 11 is enlarged by the deflection of flexible diaphragm 1-3downward through the action of pump arm 14 which is activated ofi theeccentric 15. The fuel drawn into pump chamber 11 by this suction strokeis forced through delivery valve 16 from pump chamber 11 by the returnof diaphragm 13 through the action of compression spring 17 which wascompressed on the suction stroke. The fuel flows by line 18 from fuelpump it) to the carburetor (not shown). Water jacket housing w,constructed of a porous metal and containing many fine capillary holesthrough which Water can diffuse to the outer surface, is attached tohousing 20 of pump chamber ll in such a manner as to form a water cavity21.

Water is supplied to water cavity 21 from water reservoir 22 throughline 23. The water is forced from reservoir 22 by air pressure developedby the movement of plunger 24 in pressure cylinder 25 against thetension of compression spring 26. Plunger 24 is depressed manually bythe operator, and check valve 27 in the piston of plunger 24 permitsplunger 24 to be returned to its original position after the compressionstroke. The air pressure developed in pressure cylinder 25 istransmitted to the outer concentric tube 28 of the gas-lift tube assembly 29 by line 30. The closure of gas-lift assembly 29 does notprovide a seal for the water supply and thus allows air to enter so asto displace the water used in the porous water jacket. A vent can beprovided in the closure of water supply if desired. Thus, in thisembodiment, the operator manually transports Water from reservoir 22 towater cavity 21 of fuel pump whenever it is necessary to cool thecritical parts of the fuel pump through evaporation of the water fromthe surface of water jacket housing 19.

In Figure 2 of the drawing, wherein similar reference charactersdesignate similar parts in Figure l, is shown an embodiment of thisinvention employing automatic means for regulating the How of water tothe fuel pump in accordance with the temperature of the fuel enteringthe fuel pump. This drawing is diagrammatic in nature and the componentsof the fuel system are not necessarily located in their proper spacialrelationship. In this embodiment, however, the water supply is placed ata level above the fuel pump because the water flows by gravity from thesupply to the water jacket. A thermostat 31, located in flow chamber 32at the entrance of fuel line 12 into pressure chamber 11 of fuel pump10, is employed to detect the temperature of the fuel entering the fuelpump and regulate the degree of opening of control valve 33 in waterline 34. Water flows from reservoir 22a by gravity'through line 34,float chamber 35, and line 23, to water cavity 21 of fuel pump 10. Floatchamber 35 is provided with an air return line 36 attached to the top ofreservoir 22:: and an atmospheric vent 37 so that the regular flow ofwater to fuel pump 10 in accordance with the opening of valve 33 ismaintained. In operation, the position of valve 33 is established bythermostat 31 so as to provide sufiicient cooling of the critical partsof fuel pump 10 by the evaporation through the porous structure of waterjacket housing 19.

The embodiments described in this invention are directed to theconstruction of the fuel pump with a water jacket of porous material. Itis also within the scope of this invention to provide the carburetorbowl and other components of the fuel system in which the prematurevaporization of fuel is likely to occur with a water jacket of porousmetal or other porousmaterial. In these constructions, the flow of watermay also be regulated in the manner shown in the two embodiments of thedrawing.

It is within the scope of this invention to eliminate cavity 21 in theporous metal jacket for the fuel pump and other components of the fuelsystem. In this modification a continuous porous metal covering will beem ployed and water will be introduced, from line 23, at the highestpoint of the porous metal evaporator and can be dripped or sprayed uponthe surface of the porous metal or introduced into the interior of theporous metal jacket. In this modification the void spaces in the porousmetal constitute the water jacket and the evaporation is, in effect,from the surface of the fuel pump itself.

Variations and modifications are possible within the scope of thedisclosure of the invention, the essence of which is the provision of aporous metal water jacket surrounding those portions of the fuel systemof an internal combustion engine wherein vaporization of the liquid fueltends to occur so as to prevent the condition known as vapor-lock.

What is claimed is:

l. A fuel pump for an internal combustion engine comprising a housingmember; a diaphragm positioned in said housing member so as to bisectsaid housing member and to form a fuel pump chamber in said housingmember; means for flexing said diaphragm so as to alternately increaseand decrease the volume of said pump chamber; valved fuel inlet andoutlet means in said pump chamber; a porous metal water jacket encasingthe portion of said housing member forming said pump chamber; and meansfor supplying water to said water jacket.

2. The fuel pump of claim 1 wherein the means for supplying water tosaid Water jacket comprises a manually operated air-lift device in awater supply communicating with said water jacket.

3. The fuel pump of claim l wherein the means for supplying water tosaid water jacket comprises a water supply located at a level above saidfuel pump; a conduit connecting said water supply to said water jacket;a valve in said conduit vso as to control flow therethrough; and, atemperature sensitive member exposed to the temperature of said fuelpump and operatively connected to said valve.

4. In a liquid fuel system for an internal combustion engine comprisinga liquid fuel supply, a fuel pump and a carburetor; conduit meansconnecting said fuel supply to said fuel pump, and conduit meansconnecting said fuel pump to said carburetor the improvement comprisinga porous metal water jacket encasing said fuel pump; a water supply;conduit means connecting said water supply to said water jacket; andmeans for supplying water from said water supply to said water jacketwhen fuel vaporizing conditions obtain in said fuel pump.

5. The fuel system of claim 4 wherein the means for supplying water tosaid water jacket comprises a manually operated air'lift deviceoperatively connected to said water supply.

6. The fuel system of claim 4 wherein the means for supplying water tosaid water jacket comprises a valve in said conduit means connectingsaid water supply to said water jacket so as to control flowtherethrough; and a tem perature sensitive device subjected to thetemperature of said fuel pump and operatively connected to said valve.

No references cited.

a j l

